Canine Cataracts
Can Cause Blindness

Critter Crusaders

Jovi, a senior Yorkie mix, is blind due to canine cataracts. But his lack of sight has not dampened this little guy's enjoyment of life.

Snapshot: Canine Cataracts
Here's a quick overview if you're in a hurry. Come back later when you have time to read the complete guide.

  • Symptoms: A cataract is opaque, meaning light cannot pass through it. Looking at the cataract, you will see a white cloudy saucer. If the cataract is small, the dog will have some vision remaining. However, if the cataract is large, the dog will likely be blind in that eye. And if a dog has cataracts in both eyes, he will likely be totally blind.
  • Diagnosis: If you suspect your dog has cataracts, visit your veterinarian immediately. It is possible that the "milkiness" you see is nuclear sclerosis, a natural aging of the eye that does not affect sight. It can be difficult for a dog's caregiver to detect the difference between these two eye conditions.
  • Causes: Cataracts are often caused by genetic predisposition, but can also be related to injury, old age issues and diabetes mellitus.
  • Treatment: There is no proven medical treatment for preventing or reversing cataracts. The only solution to cataracts is surgical removal, similar to the procedure performed in humans. However, if your dog's sight is not greatly impaired, surgery may be avoided.

A dog with cataracts may bump into furniture in familiar surroundings, squint, or be reluctant to run or play because his eye sight is impaired. Redness may be seen in or around the eye. The dog's caregiver may also notice a change in the dog's eye color.

Nuclear Sclerosis: Mistaken for Canine Cataracts

Nuclear sclerosis occurs as a dog ages. The eye looks cloudy but the dog can still see through the lens. See photo at right. 
©Copyright Joel Mills

If you suspect your dog has cataracts, visit your veterinarian immediately. If your dog does in fact have cataracts, delaying surgery, if the condition warrants it, can lead to greater vision and health issues such as glaucoma (a build up of pressure in eye, which is quite painful) or retinal detachment. A condition called nuclear sclerosis looks very much like a cataract, but does not affect eyesight. It can be difficult for dog caregivers to distinguish between these, which is why it is essential to get the opinion of a veterinarian.

Your veterinarian will use a special instrument to check the pressure inside your dog's eye and will also use his hand (or an object) to see if your dog follows movement with his eyes. The pupils will be dilated using a penlight and an ultrasound may be given if your vet suspects that retinal degeneration is occurring in addition to the cataracts. If your vet suspects cataracts, you may be referred to a veterinary ophthalmologist, who specializes in animal eye diseases.

Cataracts can be inherited (the dog is born with it), genetically predisposed (its genes make it likely to develop the condition) or related to old age. Canine cataracts can also be caused by injury to the eye, by a toxin, or by internal disease such as diabetes mellitus. A canine cataract can also be caused by an infection inside the eye or by retinal disease. Of these, genetics is the most common cause. Breeds often born with a predisposition to cataracts are Boston Terriers, Miniature Schnauzers and West Highland White Terriers.

In his book, Natural Health for Dogs & Cats, Dr. Richard Pitcairn states the following with regard to canine cataracts: "This condition, however, is also a frequent accompaniment of chronic disease and immune disorders in dogs. Many of the dogs with chronic skin allergies, hip dysplasia and ear problems will develop [cataracts] as they get older. Cataracts are also more common in animals that have diabetes mellitus, even with insulin treatment. Veterinarians sometimes remove the lens surgically, and this may help.Unless the underlying condition is satisfactorily addressed, however, the eye is never really healthy. Prevention, by treatment of the chronic illness, is really the only effective method."

Once a cataract has developed, the only solution is to surgically remove the lens of the eye and replace it with an artificial lens.

Canine cataract surgery is both invasive and expensive, so it should only be undertaken if it will alleviate pain or restore sight.

Untreated Canine Cataracts
If your dog's sight is not greatly impaired, surgery may not be necessary. On the other hand, you may also elect not to take the surgery route even if your dog does have sight loss. If your dog's cataracts are not causing inflammation, pain or glaucoma (pressure in the eye), you may not feel that surgery is necessary. Blind dogs can enjoy a good quality of life, as long as their caregiver is sensitive to their needs. As your dog's best friend, you will need to weigh restoring your dog's sight against the expense and potential risks of surgery.

Please keep in mind, the information on this web site is for educational purposes. It is always essential to contact your veterinarian if your canine friend "is not himself." To find a canine eye specialist, contact the American College of Veterinary Ophthalmologists.

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